A polymer film modified sensor for voltammetric determination of uric acid in the presence of ascorbic Acid and its application in urine.

A novel uric acid electrochemical sensor was fabricated by electropolymerization on glassy carbon electrode (GCE) with 4-(2-pyridylazo)-resorcinol (PAR) and its electrochemical property was investigated through cyclic voltammetry. The effect of film thickness on the oxidation response was also studied by electropolymerized scan times. The voltammetric behavior of uric acid (UA) was studied with the poly PAR modified GCE. The modified GCE was used to electrochemically detect the individual of UA and the mixture of UA and ascorbic acid (AA) by cyclic voltammetry (CV) or differential pulse voltammetry (DPV) method. For the ternary mixture containing UA and AA, the two compounds can well be separated from each other at a scan rate of 100 mV s(-1) with a potential difference of 345 mV in DPV between UA and AA. The peak currents of UA oxidation increase linearly with the concentration in ranges of 1.0x10(-8)-5.0x10(-5) mol l(-1), and the detection limits (S/N=3) was 1.0x10(-9) mol l(-1). This method was successfully applied to the determination of uric acid in human urine samples.